In the direct reduction of iron from ore mixed with an excess of coke and with heating of the mixture to elevated temperatures substantially exceeding the Curie point of iron, the ferrous component of the ore is reduced to iron, the process producing a flow of particles of the iron and excess coke. For further processing the iron particles must be separated from the coke particles so that the separated iron particles can be by heating made into an iron melt which can be refined into steel by techniques involving melting of the iron particles.
Because the direct reduction of the iron ore into iron is effected by heat, the mixture of iron and excess coke particles leaving that stage of the process are, of course, at elevated temperatures substantially above the Curie point of the iron particles. The use of prior art apparatus and methods for separating the iron particles from the coke, requires cooling of the mixture not only to below the Curie point of the iron particles, but also to substantially lower temperatures demanded by the practical operating requirements of prior art magnetic separators. Because this substantial cooling is required, the subsequent melting of the iron particles, required for the production of a melt which can be processed into steel, involves a high reheating cost.
It follows that if the hot mixture of the magnetic particles comprising the iron, could be separated from the equally hot non-magnetic coke particles, that a substantial cost saving could be effected, because the magnetic particles could be passed on for reheating at a lower cost to effect the formation of a melt for refining purposes.